In the printing industry, various printing procedures are used, with variously configured printing machines. One factor common to the various printing procedures is that toner is applied to print material and then fixed to it. Various state-of-the-art solutions have been proposed for fixing toners to print material; one typical solution is to have a heated fixing roller come into rolling contact with the print material, and the toner is then fixed on the print material by pressure and heat. To facilitate detachment of the fixing roller from the print material, the fixing roller is provided with a release oil. The fixing oil is applied using rollers onto the fixing roller, with the rollers making contact with the fixing roller. Setting the dosage of the release oil depends critically on the roughness of the roller, as well as on the mechanical settings of blades, which impinge on the rollers and have an influence on the amount of release oil on the rollers.
Release oil collects on the fixing roller and on a back-up pressure roller, which is arrayed to oppose the fixing roller and provides a reverse pressure to the fixing roller. The print material is conveyed between the fixing roller and the back-up pressure roller. It is customary in cleaning release oil from the fixing roller and back-up pressure roller to affix a blade on the back-up pressure roller and cleaning roller, which come in rolling contact with the fixing roller and back-up pressure roller. The blade and the cleaning roller remove excess release oil from the fixing roller and the back-up pressure roller.
One disadvantage is that the release oil is provided in inexact doses, leading to excess release oil being transferred onto the print material. The release oil is visible on the print material and reveals itself in the gloss of the image on the print material. Excess release oil is transported through the printing machine, contaminating components of the printing machine and becoming deposited on it, particularly on the blade for the removal of release oil. From the components contaminated with release oil, the release oil can get onto the print material and cause defects on the print material, e.g. by smearing the image.